Divergent Access to (1,1) and (1,2)-Azidolactones from Alkenes using Hypervalent Iodine Reagents

A versatile synthesis of azidolactones through azidation and cyclization of carboxylic acids onto alkenes has been developed. Based on either photoredox or palladium catalysis, (1,1) and (1,2) azido lactones can be selectively synthesized. The choice of catalyst and benziodoxol (on)e reagent serving as azide source was essential to initiate either a radical or Lewis acid mediated process with divergent outcome. These transformations were carried out under mild conditions using a low catalyst loading and gave access to a large scope of azido lactones

Cyclic Hypervalent Iodine Reagents for Azidation: Safer Reagents and Photoredox-Catalyzed Ring Expansion

Azides are building blocks of increasing importance in synthetic chemistry, chemical biology, and materials science. Azidobenziodoxolone (ABX, Zhdankin reagent) is a valuable azide source, but its safety profile has not been thoroughly established. Herein, we report a safety study of ABX, which shows its hazardous nature. We introduce two derivatives, tBu-ABX and ABZ (azidobenziodazolone), with a better safety profile, and use them in established photoredox- and metal-mediated azidations, and in a new ring-expansion of silylated cyclobutanols to give azidated cyclopentanones

Synthesis of Nitrile-Bearing Quaternary Centers via an Equilibrium-Driven Transnitrilation and Anion-Relay Strategy

The efficient preparation of nitrile-containing building blocks is of interest due to their utility as synthetic intermediates and their prevalence in pharmaceuticals. As a result, significant efforts have been made to develop methods to access these motifs which rely on safer and non-toxic sources of CN. Herein, we report that 2-methyl-2-phenylpropanenitrile is an efficient, non-toxic, electrophilic CN source for the synthesis of nitrile-bearing quaternary centers via a thermodynamic transnitrilation and anion-relay strategy. This one-pot process leads to nitrile products resulting from the gem-difunctionalization of alkyl lithium reagents.<br /

Cyclic Hypervalent Iodine Reagents for Azidation: Safer Reagents and Photoredox Catalyzed Ring Expansion

Azides are building blocks of increasing importance in synthetic chemistry, chemical biology and materials science. Azidobenziodoxolone (ABX, Zhdankin reagent) is a valuable azide source, but its safety profile has not been thoroughly established. Herein, we report a safety study of ABX, which shows its highly hazardous nature. We further introduce and study two derivatives, tBu-ABX and ABZ (azidobenziodazolone). ABZ displayed a similar reactivity but a better safety profile than ABX, and could be used in established photoredox- and metal-mediated azidation processes, as well as in a new ring-expansion of silylated cyclobutanols to give azidated cyclopentanones

Cyclic Hypervalent Iodine Reagents for Azidation: Safer Reagents and Photoredox Catalyzed Ring Expansion

Azides are building blocks of increasing importance in synthetic chemistry, chemical biology and materials science. Azidobenziodoxolone (ABX, Zhdankin reagent) is a valuable azide source, but its safety profile has not been thoroughly established. Herein, we report a safety study of ABX, which shows its highly hazardous nature. We further introduce and study two derivatives, <i>t</i>Bu-ABX and ABZ (azidobenziodazolone). ABZ displayed a similar reactivity but a better safety profile than ABX, and could be used in established photoredox- and metal-mediated azidation processes, as well as in a new ring-expansion of silylated cyclobutanols to give azidated cyclopentanones